Refactor navigator.connect code to make it more flexible.

content/public/browser/navigator_connect_service_factory.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CONTENT_BROWSER_DEVICE_SENSORS_AMBIENT_LIGHT_MAC_H_
-#define CONTENT_BROWSER_DEVICE_SENSORS_AMBIENT_LIGHT_MAC_H_
+#ifndef CONTENT_PUBLIC_BROWSER_NAVIGATOR_CONNECT_SERVICE_FACTORY_H_
+#define CONTENT_PUBLIC_BROWSER_NAVIGATOR_CONNECT_SERVICE_FACTORY_H_
 
-#include <IOKit/IOKitLib.h>
+#include "base/callback.h"
 
-#include "base/memory/scoped_ptr.h"
+class GURL;
 
 namespace content {
 
-// Provides an interface to retrieve ambient light data from MacBooks.
-class AmbientLightSensor {
+struct NavigatorConnectClient;
+class MessagePortDelegate;
+
+// Implement this interface to provide a new kind of navigator.connect
+// accessible service.
+// Instances of this class are owned by NavigatorConnectContext. Register new
+// factories by calling NavigatorConnectContext::AddFactory.
+class NavigatorConnectServiceFactory {
  public:
-  // Create AmbientLightSensor object, return NULL if no valid is sensor found.
-  static scoped_ptr<AmbientLightSensor> Create();
+  // Call with nullptr to indicate connection failure. Ownership of the delegate
+  // remains with the factory. It is assumed that for the passed
+  // MessagePortDelegate implementation the route_id and message_port_id of a
+  // connection are the same.
+  using ConnectCallback = base::Callback<void(MessagePortDelegate*)>;
 
-  ~AmbientLightSensor();
+  virtual ~NavigatorConnectServiceFactory() {}
 
-  // Retrieve lux values from Ambient Light Sensor.
-  bool ReadSensorValue(uint64_t lux_value[2]);
+  // Return true if this factory is responsible for handling connections to the
+  // |target_url|. The most recently added factory that returns true for a
+  // particular url is picked to handle the connection attempt.
+  virtual bool HandlesUrl(const GURL& target_url) = 0;
 
- private:
-  AmbientLightSensor();
-
-  // Probe the local hardware looking for Ambient Light sensor and
-  // initialize an I/O connection to it.
-  bool Init();
-
-  // IOKit connection to the local sensor.
-  io_connect_t io_connection_;
-
-  DISALLOW_COPY_AND_ASSIGN(AmbientLightSensor);
+  // Called to try to establish a connection. Only called if this factory was
+  // the most recently added factory that returned true from |HandlesUrl| for
+  // the url being connected to.
+  virtual void Connect(const NavigatorConnectClient& client,
+                       const ConnectCallback& callback) = 0;
 };
 
 }  // namespace content
 
-#endif  // CONTENT_BROWSER_DEVICE_SENSORS_AMBIENT_LIGHT_MAC_H_
+#endif  // CONTENT_PUBLIC_BROWSER_NAVIGATOR_CONNECT_SERVICE_FACTORY_H_